Rift - Beverley Birch

In a vast African landscape, four teenagers and a journalist vanish without a trace from a camp below a steep rock ridge. As Ella, the sister of one of the missing girls, helps Inspector Murothi piece together what happened, she realizes there are terrifying possibilities for her sister and the four others. There has been sinister behavior and bullying in the camp where the missing were staying. Has there been foul play? Then one of the missing turns up?but with no memory of what has happened. As the search helicopters continue their constant hum over the rock ridge, Ella and the inspector begin to wonder whether they are already too late.